9507549 Wurtele The maintenance of a balance between anabolism and catabolism is crucial to the net biosynthesis of phytochemicals. This metabolic balance is particularly evident during seedling development when large quantities of seed reserve (lipids, proteins, and carbohydrates) are catabolized. The resultant intermediates are then utilized as substrates for the biosynthesis of new phytochemicals, or they are respired to generate ATP, which supports the biosynthetic reactions. These metabolic interconversions require the coordinate action and regulation of many antagonistic processes. This award will study the catabolism of leucine and subsequent utilization of the derived carbon in young seedlings of soybean and Arabidopsis, as an example of how organisms coordinate complex interconnected metabolic pathways to achieve net interconversions of biomolecules. In plants, the catabolism of leucine is thought to occur in mitochondria, via a set of reactions which are partly in common with a pathway by which mevalonate may be metabolized to non-isoprenoid compounds. Acetyl-CoA thus formed from leucine and mevalonate can be further metabolized for respiration, gluconeogenesis, and lipogenesis. These investigations will define previously unknown mitochondrial metabolic processes and begin to indicte how they interface with metabolism in other organelles. The understanding of catabolic provesses will ultimately provide a better understanding of how plants maintain a balance between anabolism and catabolism. Comprehension of how this balance is regulated may open new, as yet unforeseen, avenues to the improvement of agricultural production.
